package com.websocket.rockwebsocket.config;

import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import org.springframework.stereotype.Component;

@ServerEndpoint("/webSocket/{sid}")
@Component
public class WebSocketServer {

  // 静态变量，用来记录当前连接线程，应该吧它们设计成线程安全的
  public static AtomicInteger onlineNum = new AtomicInteger();

  // concurrent包的线程安全set，用来存放每个客户端对应的WebSocket对象
  public static ConcurrentHashMap<String, Session> sessionPools = new ConcurrentHashMap<>();

  // 发送消息
  public void sendMessage(Session session, String message) throws IOException {
    if (session != null) {
      synchronized (session) {
        session.getBasicRemote().sendText(message);
      }
    }
  }

  // 给指定用户发送信息
  public void sendInfo(String userName, String message) {
    Session session = sessionPools.get(userName);
    try {
      sendMessage(session, message);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }


  //建立连接成功调用
  @OnOpen
  public void onOpen(Session session, @PathParam(value = "sid") String userName) {
    sessionPools.put(userName, session);
    addOnlineCount();
    System.out.println(userName + "加入websocket！当前人数为" + onlineNum);
    try {
      sendMessage(session, "欢迎" + userName + "加入连接！");
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  // 关闭连接时调用
  @OnClose
  public void onClose(@PathParam(value = "sid") String userName) {
    sessionPools.remove(userName);
    subOnlineCount();
    System.out.println(userName + "断开websocket连接，当前人数为" + onlineNum);
  }

  // 收到客户端信息时调用
  @OnMessage
  public void onMessage(String message) throws IOException {
    message = "客户端" + message + "，已收到";
    System.out.println(message);
    for (Session session : sessionPools.values()) {
      try {
        sendMessage(session, message);
      } catch (Exception e) {
        e.printStackTrace();
        continue;
      }
    }
  }


  // 错误时调用
  @OnError
  public void onError(Session session, Throwable throwable) {
    System.out.println("发生错误");
    throwable.printStackTrace();
  }


  private void addOnlineCount() {
    onlineNum.incrementAndGet();
  }

  public static void subOnlineCount() {
    onlineNum.decrementAndGet();
  }


}
